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Magnetic HVAC Return Grille Mount 

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Magnetic HVAC Return Grille 

Written By: Sean Michael Ragan 



Drill (1) 

Rare earth maqnets (1) 

• Pencil (1) 

T-nuts m 

Phillips screwdriver (1) 

Adhesive foam disks (1) 

Hole plugs (1) 

Screws (1) 

Screws (1) 


The return grille mounting in my new house was very sloppy, with a mixture of Molly bolts, 
toggle bolts, and bare screws in drywall. The sloppy workmanship annoyed me, and made 
swapping the filter way more work than it needed to be, so I came up with this no-tools fix. It 
could easily be adapted to any steel maintenance panel. 

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Pagel of 6 

Magnetic HVAC Return Grille Mount 

Step 1 — Gather material: 




• The critical parts are the ring magnets with one face countersunk to allow a screw head to 
sit flush. I used Magcraft part NSN0587, which includes 6 such magnets. I used all 6, as 
well as the plastic spacers that come with them. There are only four of these. 

• There are actually a couple different hardware bits called "T-nuts." The kind you want is 
shown in the photo-a threaded spacer with a disc with sharp prongs folded up at one end. 

• The sticky-back foam pads are used to prevent shock to the supermagnets when the grille 
is attached; they may not be necessary. 

Step 2 — Mark grille outline and remove. 

• In my case, years of repaintings 
had left a clear outline of where the 
grille edges meet the wall, so 
marking the wall was not 
necessary. If your wall is not pre- 
marked, trace the outline of the 
grille lightly on it with a pencil. 

• Remove whatever screws are 
holding the grille in place. Set the 
grille and the filter aside. The old 
screws can go in your junk bucket. 

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Page 2 of 6 

Magnetic HVAC Return Grille Mount 

Step 3 — Mark drill spots. 

• Position one of the magnets 
wherever you want to mount one, 
and use a marker to trace the 
location of the hole on the wall. 

• Be sure to leave enough 
clearance between the 
outline of the grille and the magnet 
to allow for the thickness of the 
grille wall. 


Step 4 — Drill holes. 

• Start each hole with a 1/16" pilot 
drill. If you hit wood behind the 
wallboard, just leave the 1/16" 
diameter hole. Otherwise, change 
drill bits and enlarge the pilot holes. 

• Use a twist drill big enough to pass 
the shaft of the T-nut. 13/64" was 
just right in my case. 

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Page 3 of 6 

Magnetic HVAC Return Grille Mount 

Step 5 — Insert T-nuts. 

• Reach in through the opening in the 
wallboard and insert the shaft of a 
T-nut into each of the holes you've 

• Press the prongs into the back 
surface of the wallboard. 

• If a hole penetrates a stud 
or other interstitial wood, a 
T-nut is not necessary. 

Step 6 — Tighten screws. 




• Put a screw through the hole in a ring magnet, making sure the countersink is on the right 

• Guide the shaft of the screw through one of the plastic spacers that came with the 
magnets, or a spare plastic or rubber washer of equal thickness. 

• If a hole is backed by wood, use a wood screw instead of a machine screw. 


• Tighten down the screw until the spacer and magnet are snug against the wall. Don't 

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Magnetic HVAC Return Grille Mount 

Step 7 — Apply foam pads. 


• Peel a foam pad off of its backing 
and stick it over the head of the 
screw and the ring magnet. 

• These foam pads are 
intended to protect the 
supermagnets, which can be brittle, 
against shock when the grille is 
attached. They may not be 
necessary, and depending on the 
thickness of your grille and its rim, 
you may want or need to omit 
them. Ditto the backside plastic 

Step 8 — Plug old grille holes 

• The holes in my return grille were 3/16" across. I found push-in locking nylon plugs 
at Home Depot that fit these perfectly. 


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Magnetic HVAC Return Grille Mount 

Step 9 — Reattach grille 

• Gently put the grille back in place and test the fit. 

• I used all six supermagnets that came in the package, but on final analysis I think 
just four-with one in each corner-would've been enough. 

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